Story Idea: UNDERTALE Edition
by Greekgeek2015
Summary: Repost from my AO3 account. These are story ideas free for anyone to use. Please tell me if you plan to write any of these because I want to read them. P. S. Ignore the numbers please.
1. Chapter 1

Chapter Text

Story idea 1)

Title: Wedding Crashers

Summary: You are about to get married to the greatest guy you've ever met on Mount. Ebbot. Sadly, fate had different ideas for you as everything came crashing down. You are now stuck in a mountain full of monsters with only a bouquet of golden flowers and your engament ring on you. Somehow you have to get back to the surface in time for the wedding.

Story: Basically, you're about to get married and, while looking for a place to have the wedding, you fall into the underground. It's set when Frisk is still in the underground and you have to somehow get back for the wedding. My idea is for the monsters getting freed and they come to the wedding at the end of the story.

Story idea 2)

Title: Curiosity Killed the Cat

Summary: The same old expression was told all the time: Curiosity killed the cat. But why didn't people talk about the end of the phrase: satisfaction brought it back. This is the story of how one can go so far, but still survive.

Story: I really don't have an idea for the story, I just like the expression and can make a summary guessing what it could be about.

Chapter Text

Story idea 3)

Title: Is It Better To Forget?

Summary: There was a reset, Sans knew that. He couldn't quiet remember all of it, but he did know some. In his hand he held a picture of him and two smiling faces, a girl on her twenties with (h/c) hair and a kid around thirteen with red hair. He cared about them so much, even though he couldn't recall their names, he just knew they were important to him. He just wish he knew why time reset.

Story: this is a Sans X Reader fanfic where for some reason time reset and not even Frisk can remember why. Sans knows some of the timeline by his machine, that allows him to keep some memories and store objects in case of a reset. Sans tries to find the girls in the picture and runs into (y/n). They start dating and soon get married, adopting a thirteen year old girl. There's some danger, most likely from Chara, throughout the story as a villain, but I can't think up of a plot for the action.

Title: Here Comes a Thought

Summary: Frisk was never in control. Not just in the genocide run, but in the entire underground. As soon as she fell Chara came and took over her body. Now, on the surface at the end of the pacifist route, Frisk is slowly getting back control. But how can she face the monsters who she has only seen through the eyes of a demon.

Story: I have this theory that has soon as Frisk fell she was being controlled. Proof as the beginning of the game when you name the fallen human or "Chara" and hat summons the demon that comes when you call it's name. I also have a theory that the player is Chara but that's for another time.

Anyway, the story is throughout the game Chara is like Flowey, a soulless creature with a vessel trying to get some entertainment. After all the neutral, pacifist, genocide, and anothe pacifist run they're on the surface. But back on the surface, Frisk gets control back and she needs to tell the monsters who she sort of cares about that she has never actually talked to any of them face to face. How will they react to their Frisk being a lie? You decide!

Also, in the underground Frisk gets control everyone once in while. When ever the game doesn't say "you did_" that's when Frisk breaks free. Like when she told Asriel her name.

Title: I Survived the Underground, I Can Survive High School

Summary: You'd think that high school would be a piece of cake for Frisk. Nope! The monsters not being allowed to go to school yet so she's all alone with a bunch of humans who either hate her or depressed. The school itself is pathetic, it never being cleaned and looking like a dump. Somehow, Frisk's gonna turn this school around!

Story: Basically, Frisk goes to a human high school and helps it become a better place, while still being the ambassador to monsters. She helps the school get cleaned up, students more active, and helping anyone in need.

Chapter Text

Story idea 7)

Title: Flirting With Death

Summary: Reapertale Au. When Frisk was created as the Angel (or other thing, I don't know that much about what she is in this AU) of Mercy, she always flirted with everyone. But when she meets the reaper, he seems more fun to play with.

Story: Basically, Reapertale AU, Frisk X Sans. Frisk flirts with Sans, who blushes like crazy, meaning nothing by it and only doing it to see how the skeleton reacts. Soon, Sans realizes he actually has feeling for the angel and tries to hide it. Chara comes along to wreck everything and Frisk and Sans have to work together. The story ends, as I imagine, with the two kissing.

Notes: I came up with the title after looking at fanart called "Frisk Uses Flirt".

Now for a different story with the same title:

Summary 2: Frisk always knew she meet the reaper, she just didn't expect to see him so soon. At the end of the genocide route, the human knows what the reaper looks like, not tall with a black cloak, but short with a blue hoodie. After all the resets she's done, Frisk realized this could be her last.

Story 2: Another Sans X Frisk, but no Chara in the story. Frisk resets over and over again to find all the endings, also, she doesn't really feel any emotion, since she thinks she can jus reset and fix it, and Sans is sick of it. At the end of the geno route, Frisk feels the weight of her actions as Sans can truly destroy her soul. She resets for the last time and tries to actually feel everyone's pain, but the pain could be to much to bear, so she turns to Sans. He helps her to try to become a better person and they slowly fall in love.

Title) Stars

Summary) If you look up at the sky, you'll see stars. Millions of sparkling lights that fill your life with wonder.

But there used to be more.

Story) Reader X Sans. You like to look at stars and you work at a Planetary. One day you meet Sans, who was alive back when monsters were first on the surface, who loves stars too. Yall start talking and he explains how he saw hundreds more stars from before. You soon start meeting his friends and you start to have feelings for him. You start to create a simulation on a machine, with the help of Alphys, of the stars from before the monsters were put away. You show Sans the simulation and that's where you start dating. You can continue how ever you want to.

Title) But it re... Fused?

Summary) *You call for help  
*0 HP  
*Game Over  
*But it re...fused?

During the battle with Asriel you call out to the other human souls and they do something no one expected.

Story) While battling Asriel you call for help from the human souls. They come help you by fusing into your soul, you defeat Asriel. After that you realize you have the power of a god and can't get rid of that power. Now you have to go through everyday life and control your magic. Oh... You also have to hide it from your family, besides Sans, he's helping you control and hide it, and the entire world. I also imagine Frisk going to a human school while doing this. This is Frisk's point of view.

Chapter Text

Title) The Weight of a Crown

Summary) Being King takes a lot of responsibilities, even if you don't want them.

Sometimes, you have to do something against your morals. You push away your family and loved one, but is there a way to get them back?

Story) After the neutral run, Flowey does not kill Asgore. Asgore meets ToRIEL again with the help of Frisk and wants to make amends. He tries everything to get things back to the way they were before he was forced to kill those souls. But, things can't ever go back to before. Flowey steals the human souls, not the monsters, and Frisk and the rest have to battle him. Asgore sacrifices his HP down to 1 for Toriel. After the battle is over, Toriel heals Asgore and tells him she will never forgive him, but they can start by being friends.

Title) The Weight of a Crown

Summary) Papyrus never wanted this job, his brother was supposed to have it. The job forced him to do things he wasn't proud of. All he wanted was his family back.

But that could never happen when your father is dead and your brother is missing.

Story) AlterTale AU (for those who don't know, in this AU Sans is Toriel, Papyrus is Asgore, Gaster is Asriel/Flowey, and vice versa). Sans ran away to ruins even though he was supposed to be king, that forced his brother Papyrus to become King. Papyrus killed the six souls and when Frisk comes, Gaster steals all the souls. When he is defeated Papyrus sees Sans again who is angry at him for killing kids. they go up to the surface and the rest of the story is Papyrus trying to make up his mistakes. Also, Sans adopts Frisk.

Chapter Text

Title) Inner Demons

Summary) "No I won't," a small girl said to nothing.

Suddenly, the girl put on a evil grin, "do it!"

The fearful face returned, "NO!"

They felt the blood on their hands...

Story) Human AU. Frisk is a girl in her teens with multiple personality disorder and she's in a mental ward for being too dangerous. The doctors give each personality a name- the one she is most of the time is the pacifist personality, the more deadly one is the genocide personality, and the other six barly show up, one shows up every year, are called bravery, Justice, kindness, patience, integrity, and perseverance. The genocide personality calls her self Chara.

The doctors that take care of her are Doctor Gaster and Doctor Alphys. Her best and only friend is Asriel. Asriel also has multiple personality disorder, but he only has one that shows up a lot named Flowey, who is psychotic and who gets along with the Chara personality, and is son of the mayor.

One day, Chara gets loose and fully takes over Frisk's pacisifist personality. Frisk must fight her inner demons to get rid of the personalities once in for all.

Title) Few Fuse

Summary) "Run, Frisk!" A boy shouted, who was holding a pink glowing shield, holding back a monster that had a gem in it.

"STEVEN!" Frisk ran towards the boy and blocked a blow that would hit his side.

"ARGH!" Steven pushed back the monster a bit and ran towards the kid. "Frisk, are you all right?"

He grabbed her hand and hugged her, causing a bright light to appear.

Story) Steven Universe and Undertale xover. Frisk frees the monsters and she and the monsters live in Beach City. She meets Steven and the gems and thinks it's cool. One day, the gems go on a mission, the monsters have to go to another town for a day, and Connie is busy at school, so Frisk and Steven play together. A gem monster attacks and Frisk gets injured. Steven runs to her and they accidentally fuse into Fren.

When they defeat the monster they learn Frisk can fuse because of her Determintaion!

Chapter Text

Title) Child of Determination

Summary) Frisk escaped the Underground with nothing but her memories.

Years later, her child called down the mountain.

Story) post neutral, Asgore is dead. Frisk leaves the underground but can't go back in. She grows up and ends up writing a book about her adventures, but calling it fiction. It becomes famous and on the one year anniversary of its publishing, Frisk, her child, and her publisher and a couple of other people, go to Mount. Ebbot to have a party. Frisk's child (which I think should be named after a font, so I'm using the name Lily) Lily was supposed to play her trumpet at the party but she goes exploring and falls down the hole with nothing but her trumpet and her moms book. Lily meets Flowey, who at first thinks she's Frisk, but then Sans appears. Sans finds out who Lily is and wakky adventures follow since Lily knows everything about the underground from her moms book. Soon, she starts hearing the voice of Chara Telling her about a darker route. Lily gets confused about the spirit Chara since she knows nothing of her. Different things happen, but the story ends with Lily setting the monsters free.

Title) My Father

Summary) Years ago, a baby named Frisk fell down from the serface. A certain skeleton finds them and becomes their adoptive father.

Now, Frisk is all grown up and wants to see the underground that her father tells her about.

Story) Frisk falls as a baby, her parents were trying to get rid of her, and Sans adopts her. He keeps her secret for years in a secret house in the woods. (Also, she and Sans go to talk to Toriel when no one is looking) One day, when Frisk is sixteen, she wants to go explore the underground, but Sans says no. She sneaks out and ends up at the beginning of Snowdin. She runs into Papyrus and Sans, who tries to pretend that he doesn't know her. When Papyrus leaves, Sans pulls Frisk aside and explains to her that everyone in the underground wants to kill her. Frisk is determined though, so she goes through the underground befriending everyone. At the end of the Pasicist run Flowey tells everyone about how Sans adopted Frisk years ago, but no one was mad. Seeing that him saying that failed in getting a reaction, Flowey stole all the soul. The story ends with the monsters being freed.

I feel like this story could have a sequel with a Frisk reacting with human stuff, since she doesn't have memories of other humans, but I don't know.

Title) Les Miserables

Summary) Sans as an escaped convict tries to live his life, but people don't seem to forget him.

Story) Les Mis story, Human AU. Follows the plot of Les Miserables

Sans: Jean Valjean  
Toriel: Fantine  
Frisk: Cossete  
Chara: Epponie  
Asriel: Marius  
Javert: Undyne  
Friends of the ABC: random monsters and the souls

Title: The Miserable Monsters

Summary) Frisk doesn't only fall down a mountain- she falls into a revolution!

Story) Les Mis AU. The monsters want Asgore to stop the war on humans, sit they start a revolution in the underground. Frisk falls down and is adopted by Toriel, who has the same story as the game. Toriel dies in one of the battles and leaves Frisk to Sans, an old prisoner for hiding humans. Frisk and Asriel meet, Asriel ran away from his father because of the war, and fall in love. Chara, who also ran away from her home in the castle to save herself from being killed for doing something wrong, loves Asriel. (The friends of the ABC are the six humans who fell down and managed to stay hiddened and other monsters. They are being tracked down by the Royal guard) The story then follows the plot of les mis. Except, Asgore stops the war, but almost everyone who participated in the revolution is dead. The story ends as Asriel and Frisk become the King and Queen of the underground and they learn about Sans dying in his old house in Snowdin.


	2. Chapter 2

Title: Reborn

Summary: The six souls have been held so long, they don't want to move to what ever's next. So, it seems they want to live again.

Story: after the pacifist run, the souls are released, but they don't move on. They somehow are reborn into babies with no memories. When they grow up they are found by Frisk, who is in their thirties and the souls in their twenties, and they realize that they were the souls that were lost. Slowly, they all remember their lives in the underground. Continue the story.

Title: The Seven Mages

Summary: What do all the humans that fell have in common? They're all related to very mages who trapped the monsters in there.

Story: the seven mages who cast the barrier had descendants- I believe each Mage has a different color soul like the humans that fell, so the Orange soul is related to the Orange Mage- who all fell into the underground. I don't know what else you could do with this, I just thought it would be a cool start.


End file.
